Process for the production of cement clinker in the rotary kiln intake chamber

Abstract

In cement clinker production installations, especially with short rotary tubular kiln, in order to find a way in which the thermally highly stressed rotary kiln intake chamber can be protected from overstress and therewith the entire production installation can be reliably operated it is proposed, according to the invention, to introduce directly into the rotary kiln intake chamber, a finely granular non-preheated substance usable in the cement clinker production process, to suspend or disperse it there in the rotary kiln exhaust gas and thereby to continuously cool the kiln intake chamber, and to discharge the heated finely granular substance with the exhaust gas from the kiln intake chamber and to add it to the process raw meal or direct it elsewhere.

We claim as our invention:  
     
       1. A process for the production of cement clinker from raw meal which is preheated in at least one heat exchanger train traversed by exhaust gas from a rotary tubular kiln having a cyclone suspended gas-heat exchanger system, said raw meal being precalcined if necessary in a precalcination stage and burned in a sintering zone of the rotary tubular kiln into cement clinker, which cement clinker is cooled in an after-engaged clinker cooler, in which process there are used in the precalcination stage the exhaust gas stream from the rotary tubular kiln and an exhaust air stream from the clinker cooler, separately or together, for the precalcination of the raw meal, comprising the steps of introducing a fine granular non-preheated substance usable in the cement clinker production process directly into an intake chamber of the rotary kiln, suspending or dispersing the fine granular substance there in the rotary kiln exhaust gas and thereby continuously cooling the kiln intake chamber, after which the heated fine granular substance with the exhaust gas is discharged from the kiln intake chamber. 
     
     
       2. A process according to  claim 1 , wherein said heated fine granular substance, after being discharged from the kiln intake chamber, is added to the process raw meal. 
     
     
       3. A process according to  claim 1 , wherein a non-preheated cement raw meal is used as the fine granular substance to be introduced into the rotary kiln intake chamber. 
     
     
       4. A process according to  claim 1 , wherein a raw meal component is used as the fine granular substance to be introduced into the rotary kiln intake chamber. 
     
     
       5. A process according to  claim 1 , wherein kiln filter dust is used as the fine granular substance to be introduced into the rotary kiln intake chamber. 
     
     
       6. A process according to  claim 1 , wherein the fine granular substance, introduced into the rotary kiln intake chamber and dispersed there, is discharged from the intake chamber over a separate partial gas lead-off line. 
     
     
       7. A process according to  claim 1 , wherein the fine granular substance to be introduced into the rotary kiln intake chamber is introduced into the intake chamber in the elevation range between a raw meal inflow chute and an upper side of the kiln intake chamber. 
     
     
       8. A process for the production of cement clinker from raw meal comprising the steps of: 
       preheating raw meal in at least one heat exchanger train comprising a cyclone suspended gas-heat exchanger system;  
       directing exhaust gas from a rotary tubular kiln through said heat exchanger train;  
       precalcining said raw meal in a precalcination stage;  
       thereafter directing precalcined meal into a sintering zone of the rotary tubular kiln;  
       thereafter burning said raw meal into cement clinker in the sintering zone of the rotary tubular kiln;  
       thereafter cooling said burnt cement clinker in a clinker cooler;  
       directing an exhaust air stream from the clinker cooler into the precalcination stage;  
       directing an exhaust gas stream from the rotary tubular kiln into said precalcination stage;  
       introducing a fine granular non-preheated substance directly into an intake chamber of the rotary tubular kiln;  
       thereafter disbursing the fine granular substance into the rotary kiln exhaust gas to continuously cool the kiln intake chamber;  
       thereafter discharging the now heated fine granular substance with the exhaust gas from the kiln intake chamber.  
     
     
       9. A process according to  claim 8 , wherein said heated fine granular substance, after being discharged from the kiln intake chamber, is added to the raw meal in the precalcination stage. 
     
     
       10. A process according to  claim 8 , wherein a non-preheated cement raw meal is used as the fine granular substance to be introduced into the rotary kiln intake chamber. 
     
     
       11. A process according to  claim 8 , wherein a raw meal component is used as the fine granular substance to be introduced into the rotary kiln intake chamber. 
     
     
       12. A process according to  claim 8 , wherein kiln filter dust is used as the fine granular substance to be introduced into the rotary kiln intake chamber. 
     
     
       13. A process according to  claim 8 , wherein the fine granular substance, introduced into the rotary kiln intake chamber and dispersed there, is discharged from the intake chamber over a separate partial gas lead-off line. 
     
     
       14. A process according to  claim 8 , wherein the fine granular substance to be introduced into the rotary kiln intake chamber is introduced into the intake chamber in the elevation range between a raw meal inflow chute and an upper side of the kiln intake chamber. 
     
     
       15. A process for the production of cement clinker from raw meal comprising the steps of: 
       preheating raw meal;  
       thereafter directing said preheated raw meal through an intake chamber of a rotary tubular kiln and into a sintering zone of the rotary tubular kiln;  
       thereafter burning said raw meal into cement clinker in the sintering zone of the rotary tubular kiln;  
       introducing a fine granular non-preheated substance directly into the intake chamber of the rotary tubular kiln;  
       thereafter disbursing the fine granular substance into the rotary kiln exhaust gas to cool the kiln intake chamber; and  
       thereafter discharging the now heated fine granular substance with exhaust gas from the kiln intake chamber.  
     
     
       16. A process according to  claim 15 , wherein said heated fine granular substance, after being discharged from the kiln intake chamber, is added to the preheated raw meal. 
     
     
       17. A process according to  claim 15 , wherein at least one of a non-preheated cement raw meal, a raw meal component and kiln filter dust is used as the fine granular substance to be introduced into the rotary kiln intake chamber. 
     
     
       18. A process according to  claim 15 , wherein the fine granular substance, introduced into the rotary kiln intake chamber and dispersed there, is discharged from the intake chamber over a separate partial gas lead-off line. 
     
     
       19. A process according to  claim 15 , wherein the fine granular substance to be introduced into the rotary kiln intake chamber is introduced into the intake chamber in the elevation range between a raw meal inflow chute and an upper side of the kiln intake chamber.